def add_numbers(num_a, num_b):
    return num_a + num_b

def subtract_numbers(num_x, num_y):
    return num_x - num_y

if __name__ == "__main__":
    print("加减法程序：支持 + 和 - 运算")
    number1 = int(input("请输入第一个数字："))
    number2 = int(input("请输入第二个数字："))
    operator = input("请输入运算符 (+ 或 -)：")

    if operator == "+":
        print("结果：", add_numbers(number1, number2))
    elif operator == "-":
        print("结果：", subtract_numbers(number1, number2))
    else:
        print("错误：该程序只支持 + 和 - 运算")

    print("Hello World")